42 



fall and others in February or spring, while the tree is still dormant. 

 The cut limbs must be protected witli paint or wax to keep out bac- 

 teria or fungi. I have tried cutting back at various times in the year. 

 I have cut back in August and the trees did well. 



Mr. Neilson: What is the actual temperature that buds will 

 stand when covered with paraft'in.^ 



« 



Dr. Morris: I have found that 200 F. was borne by all except 

 peaches. Not much above 150 F. is entirely safe. 



Mr. Rick : Would you prefer to do most of your grafting when 

 the foliage is not out and the tree is still dormant.'' 



Dr. Morris: I am speaking from an experimental standpoint 

 largely. It depends upon several questions. The kind of tree and 

 amount of sugar in the sap. If dealing with walnuts it is better to 

 wait until they are almost in full leaf and the leaves pretty well 

 formed. They are grafted through June, or late May to advantage. 

 There are other ways of controlling that flow. We will ask Mr. Jones 

 to tell us about that. He is the one best qualified to speak. We have 

 grafted' hickories every month in the year. 



Mr. Bixby: You speak of grafting hickories every month in the 

 year. They have been successfully grafted every month in the year? 



Dr. Morris: Oh yes, that is a point. Success is a relative term, 

 however, and we must ask if they are grafted practically for the or- 

 chardist instead of successfully as an experiment. They have been 

 grafted so that they have gTOwn, but the proportion of catches is 

 smaller some months and larger in other montlis. The proportion of 

 catches is best during the months horticulturists have always recog- 

 nized as the best — the spring months. 



The President: You say that the enzymes from the new stock 

 growth kill the graft sprouts. That is only true of the new growth ? 



Dr. Morris : It seems that the new stock growth is specially 

 inimical to grafts. When the old foliage is trying to exercise supremacy 

 over graft sprouts it does not seem to furnish enzymes that are so 

 deadly to grafts. 



